Nutrient recovery and improvement of anaerobic digestion process by low grade magnesium oxide application

[spa] Diferentes esfuerzos han sido desarrollados para reducir la inhibición por nitrógeno amoniacal en la DA. Entre ellos, la adición de materiales con capacidad de intercambio catiónico (por ejemplo: bentonita, glauconita, fosforita y zeolitas) o materias con capacidad de adsorción (ej. arena, óxidos de magnesio, sepiolitas y zeolitas) han mostrado buenos resultados. Igualmente, en años recientes la posibilidad de acoplar la DA y la precipitación de estruvita (MgNH4PO4·6H2O) en el mismo reactor han llamado la atención. La precipitación de estruvita ocurre de manera natural cuando la concentración de 2+ + 3- Mg , NH4 y PO4 excede el producto de solubilidad de la estruvita. Con lo cual, la precipitación de estruvita en muchos sistemas de DA requiere la adición de compuestos 2+ 3- + químicos, ya que la concentración de Mg y PO4 es típicamente inferior a la del NH4 . El objetivo de este estudio es comparar el desempeño de cinco diferentes fuentes de magnesio (ej. MgCl2, Mg(OH)2, HG-MgO, LG-MgO y SA) en reactores, simultaneando los procesos de la DA y la precipitación de estruvita dentro del mismo reactor. La adición de agente estabilizante al purín de cerdo presento una máxima eficiencia de remoción de nitrógeno amoniacal total del 80%. La operación de los -1 digestores mostró que la adición de agente estabilizante de 5 y 30 g L al digestor resulta en un incremento del 25 y 40% en la producción de metano, respectivamente, comparado con el reactor de referencia. Este resultado puede estar relacionado con la reducción de la concentración de amonio y el incremento de la concentración de magnesio y concentración de partículas en el medio de digestión. Adicionalmente, los resultados de alcalinidad y ácidos grasos volátiles muestran que la adición de agente estabilizante no presenta un efecto negativo en los microorganismos anaeróbicos.[eng] Anaerobic digestion is a worldwide technology to treat organic waste streams, primarily due to its capacity to produce methane as renewable energy. However, there is an increasing interest on nutrient recovery (N and P), which from both environmental and economic reasons have been identified as key feature in anaerobic digestion plants. Controlled struvite formation has been attracting increasing attention as a near mature technology to recover nutrients from anaerobic digestion. However, struvite feasibility is generally limited by the high cost of chemical reagents. Because the economic feasibility of struvite is heavily influenced by reagent cost, several authors have trialled lower-cost magnesium sources. Studies to date on struvite precipitation with MgO have largely focused on the aqueous phase, with little attention given to the preceeding MgO dissolution. However, the observations noted above suggest that there may be opportunity to better understand, intervene and improve dissolution and access to MgO. The present study uses experiments and chemistry modelling to evaluate and better understand TAN removal from pig manure using MgO. Tests were performed with four industrial magnesium oxide (MgO) from natural magnesite calcination: a commercial high grade MgO (HGMgO) as well as a number of low-grade MgO (LGMgOs) by-products. All these MgO reagents were also pre-treated with phosphoric acid and tested separately after pre-treatment. The study focussed on the underlying chemistry to show how reactivity and dissolution of the various magnesium by-products influenced struvite precipitation and TAN removal performance. Moreover, another option to minimise struvite precipitation cost is to combine struvite precipitation and AD in the same reactor. Several authors have studied the addition of magnesium reagents (MgCl2 and Mg(OH)2) to precipitate struvite during anaerobic digestion, causing in some cases inhibition by pH or cation toxicity. However, to our knowledge, no references bave been found evaluating the utilization of magnesium by- products within the reactor to precipitate struvite during anaerobic digestion. In this study struvite precipitation and pig manure anaerobic digestion were coupled in the same reactor in order to mitigate the inhibitory effect of free ammonia and avoid precipitator costs. The stabilizing agent used to facilitate struvite precipitation was formulated with low-grade magnesium oxide by-product; an approach that would notably reduce struvite processing costs. Therefore, the feasibility of coupling anaerobic digestion and struvite precipitation in the same reactor was evaluated to enhance manure anaerobic digestion methane yields through ammonia inhibition mitigation. Five different magnesium sources were tested as struvite (ammonia sequestration agent) precursor, i.e. MgCl2, Mg(OH)2, two industrial by-products rich in MgO but with different reactivity, and a stabilizing agent. The latter was formulated in advance with the low reactivity industrial by-product and phosphoric acid. The effect of each magnesium source on anaerobic digestion as well as its struvite precipitation capacity was evaluated through a series biomethane potential test. However, a long term anaerobic digester operation was required to assess the feasibility of the process and to ensure that the stabilizing agent does not introduce any harmful compound for the anaerobic biomass. In this vein, the -3 addition of 5 and 30 kg m of the stabilizing agent in a pig manure continuous digester 3 -1 3 -1 resulted in a 25% (0.17 m kg ) and a 40% (0.19 m kg ) increase in methane production per mass of volatile solid, respectively, when compared with the reference digester (0.13 3 -1 m kg ). Moreover, the stability of the process during four hydraulic retention times guarantees that the stabilizing agent did not exert a negative effect on the consortium of microorganisms

Development of a modified plug-flow anaerobic digester for biogas production from animal manures

Traditional plug-flow anaerobic reactors (PFRs) are characterized by lacking a mixing system and operating at high total solid concentrations, which limits their applicability for several kinds of manures. This paper studies the performance of a novel modified PFR for the treatment of pig manure, characterized by having an internal sludge mixing system by biogas recirculation in the range of 0.270–0.336 m3 m−3 h−1. The influence on the methane yield of four operating parameters (recirculation rate, hydraulic retention time, organic loading rate, and total solids) was evaluated by running four modified PFRs at the pilot scale in mesophilic conditions. While the previous biodegradability of organic matter by biochemical methane potential tests were between 31% and 47% with a methane yield between 125 and 184 LCH4 kgVS−1, the PFRs showed a suitable performance with organic matter degradation between 25% and 51% and a methane yield of up to 374 LCH4 kgVS−1. Operational problems such as solid stratification, foaming, or scum generation were avoided.info:eu-repo/semantics/publishedVersio

Mapas de información colaborativa para la delimitación de predios, bicirrutas y sitios turísticos en Tunja, Boyacá

New technologies and technological advances have contributed to a greater interaction with platforms such as crowdmapping, which allow people or organizations to have an information flow with which they can make contributions through collaborative maps. In order to understand its applications and uses, a systematic review was conducted on the application and importance of crowdmapping and its contribution to the creation of maps in different sectors or areas of society. From this review, the usefulness and efficiency of this type of mapping was determined regarding the delimitation of properties and bike routes, as well as the geolocation of tourist sites in Tunja (Boyacá), so that anyone accessing the maps could participate, appropriate the information, and contribute according to their interests. Said implementation makes its contribution people to know and be able to guide and provide relevant information to both citizens and tourists on the different routes for bicycle users or tourist sites in the city. In these cases, such information is provided by people who have lived the experience and want to share it, thus creating collaborative maps in real time. As for these maps, it is important to validate all the information in order for it to be completely real and for this type of platform to generate confidence for later implementation in other projects with a social aim.Las nuevas tecnologías y los avances tecnológicos han contribuido a una mayor interacción con plataformas como el crowdmapping, que permiten a las personas u organizaciones tener un flujo informativo con el cual pueden realizar aportes a través de mapas colaborativos. Con el fin de conocer sus aplicaciones y usos, se realizó una revisión sistemática de la aplicación e importancia del crowdmapping y su contribución en la creación de mapas en diferentes sectores o áreas en la sociedad. A partir de esta revisión se determinó la utilidad y eficiencia de este tipo de mapeo en la delimitación de predios y bicirrutas, así como en la geolocalización de los sitios turísticos en Tunja (Boyacá, Colombia), con el fin de que cualquier persona que accediera a los mapas pudiera participar, apropiarse de la información y aportar según su interés. Dicha implementación muestra un aporte para que las personas conozcan y puedan guiar y brindar información relevante tanto a ciudadanos como a turistas sobre las diferentes rutas para biciusuarios o lugares turísticos de la cuidad. En estos casos, dicha información es proporcionada por personas que han vivido la experiencia y desean compartirla, creando así mapas colaborativos en tiempo real. Ante dichos mapas, es importante validar toda la información en aras de que esta sea completamente real y este tipo de plataformas genere confianza para su posterior implementación en otros proyectos con objetivo social

Tecnologias de recuperação de nutrientes para os sistemas de digestão anaeróbia: revisão

Anaerobic digestion is a worldwide technology to treat organic waste streams, primarily due to its capacity to produce methane as renewable energy. However, there is an increasing interest on nutrient recovery (N and P), which from both environmental and economic reasons have been identified as key feature in anaerobic digestion plants. The manuscript presents a comprehensive overview on recent advances in nutrient recovery technologies applicable for anaerobic digestion systems. The review focus on N and P recovery through the use of digestates as fertilizers, struvite precipitation and biological systems such as phycoremediation (i.e. algae cultivation) and polyphosphates accumulating organisms.A digestão anaeróbia é uma tecnologia mundialmente conhecida para o tratamento de resíduos orgânicos, principalmente devido a sua capacidade de produzir metano como energia renovável. No entanto, há um interesse crescente sobre a recuperação de nutrientes (N e P), que a partir de razões ambientais e econômicas têm sido identificados como elemento-chave em plantas de digestão anaeróbia. O presente manuscrito apresenta uma visão abrangente sobre os recentes avanços em tecnologias de recuperação de nutrientes aplicáveis para sistemas de digestão anaeróbia. O foco da revisão é a recuperação do N e P através do uso de fertilizantes, como digestates precipitação estruvite e sistemas biológicos, tais como phycoremediation (por ex, cultivo de algas) e organismos acumuladores de polifosfatos.La digestión anaeróbica es una tecnología mundialmente aplicada para el tratamiento de residuos orgánicos, principalmente debido a su capacidad de producir metano como fuente de energía renovable. Sin embargo, existe un creciente interés en la recuperación de nutrientes (N y P), el cual desde el punto de vista ambiental y económico ha sido identificado como un factor clave en las plantas de tratamiento vía digestión anaeróbica. El presente manuscrito presenta una visión global de los recientes avances en las tecnologías de recuperación de nutrientes aplicables a sistemas de digestión anaeróbica. La revisión está enfocada en la recuperación de N y P mediante el uso del digestado como fertilizante, la precipitación de estruvita y sistemas biológicos como la ficoremediación (ej. cultivos de algas) y organismos acumuladores de polifosfatos

Tecnologias de recuperação de nutrientes para os sistemas de digestão anaeróbia: revisão

Anaerobic digestion is a worldwide technology to treat organic waste streams, primarily due to its capacity to produce methane as renewable energy. However, there is an increasing interest on nutrient recovery (N and P), which from both environmental and economic reasons have been identified as key feature in anaerobic digestion plants. The manuscript presents a comprehensive overview on recent advances in nutrient recovery technologies applicable for anaerobic digestion systems. The review focus on N and P recovery through the use of digestates as fertilizers, struvite precipitation and biological systems such as phycoremediation (i.e. algae cultivation) and polyphosphates accumulating organisms.A digestão anaeróbia é uma tecnologia mundialmente conhecida para o tratamento de resíduos orgânicos, principalmente devido a sua capacidade de produzir metano como energia renovável. No entanto, há um interesse crescente sobre a recuperação de nutrientes (N e P), que a partir de razões ambientais e econômicas têm sido identificados como elemento-chave em plantas de digestão anaeróbia. O presente manuscrito apresenta uma visão abrangente sobre os recentes avanços em tecnologias de recuperação de nutrientes aplicáveis para sistemas de digestão anaeróbia. O foco da revisão é a recuperação do N e P através do uso de fertilizantes, como digestates precipitação estruvite e sistemas biológicos, tais como phycoremediation (por ex, cultivo de algas) e organismos acumuladores de polifosfatos.La digestión anaeróbica es una tecnología mundialmente aplicada para el tratamiento de residuos orgánicos, principalmente debido a su capacidad de producir metano como fuente de energía renovable. Sin embargo, existe un creciente interés en la recuperación de nutrientes (N y P), el cual desde el punto de vista ambiental y económico ha sido identificado como un factor clave en las plantas de tratamiento vía digestión anaeróbica. El presente manuscrito presenta una visión global de los recientes avances en las tecnologías de recuperación de nutrientes aplicables a sistemas de digestión anaeróbica. La revisión está enfocada en la recuperación de N y P mediante el uso del digestado como fertilizante, la precipitación de estruvita y sistemas biológicos como la ficoremediación (ej. cultivos de algas) y organismos acumuladores de polifosfatos

Diseño centrado en el usuario y experiencia de usuario en el sistema de control de acceso de la Universidad Libre

User-centered design has become a fundamental part of any software application development project, therefore, if you want to provide a user with a simple way to perform tasks or activities within a certain web page, platform, or application, it is essential. simplify and optimize the elements that are part of the site to provide a satisfactory user experience. This article discusses the essential elements of the user-centered design that are part of the web application for the control of capacity in the Bogota venues, developed for the Universidad Libre in order to comply with the regulations issued by the Colombian state, due to the health emergency generated by COVID-19. In addition to identifying, through a usability test, what were the different aspects that needed to be implemented so that future updates can be carried out and thus generate an improvement in the user experience, additionally a description of the planning process that was carried out and the reason why the project was proposed.El diseño centrado en el usuario se ha vuelto una parte fundamental en cualquier proyecto de desarrollo de aplicaciones de software por lo tanto si se quiere proporcionar a un usuario una manera sencilla de realizar tareas o actividades dentro de determinada página web, plataforma o aplicación es esencial simplificar y optimizar los elementos que forman parte del sitio para proporcionar una experiencia de usuario que resulte satisfactoria. En este artículo se discuten los elementos esenciales del diseño centrado en el usuario que hacen parte de la aplicación web para el control de aforos en las sedes de Bogotá, desarrollado para la Universidad Libre en orden para acogerse a las normativas impartidas por el estado colombiano, en virtud de la emergencia sanitaria generada por la COVID-19. Además de identificar, por medio de un test de usabilidad, cuáles fueron los diferentes aspectos que hicieron falta implementar para que a futuras actualizaciones se puedan llevar a cabo y de esta manera generar una mejora en la experiencia del usuario, adicionalmente se realiza una descripción del proceso de planeación que se llevó a cabo y la razón por la que se planteó el proyecto

An Assessment of Contaminants in UK Road-Verge Biomass and the Implications for Use as Anaerobic Digestion Feedstock

Biomass from harvested road-verge herbage has potential value as a feedstock for anaerobic digestion (AD) energy plants. However, the proximity to road traffic related pollution sources introduces the possibility of contamination by potentially toxic elements and polycyclic aromatic hydrocarbons. Potential sources of pollution from road traffic emissions are identified and the consequent likelihood of certain contaminants being present at elevated levels is assessed. Samples of road verge biomass harvested from selected locations in Lincolnshire UK for use in AD plants were analysed to produce a set of measurements for the presence of the contaminants of interest. The measured levels of these contaminants are compared to reported background levels in UK herbage and soils to assess if there is significant increased concentration in road-verge biomass. Samples of digestate from an AD plant using the road-verge biomass as feedstock were also analysed to determine if there is notable risk of transfer and concentration of contaminants into agricultural land where the digestate may be used for fertilisation. While elevated levels of contaminants were detected, they were not found in concentrations on road verge biomass at high enough levels to cause adverse effects or concerns for its safe use as an AD feedstock

Review of biochar role as additive in anaerobic digestion processes

because of the urgent need to provide renewable energy sources and efficiently manage the continuously growing amount of organic waste. Biochar (BC) is an extremely versatile material, which could be produced by carbonization of organic materials, including biomass and wastes, consistently with Circular Economy principles, and “tailor-made” for specific applications. The potential BC role as additive in the control of the many wellknown critical issues of AD processes has been increasingly explored over the past few years. However, a clear and comprehensive understanding of the connections between BC and AD is still missing. This review paper analyses and discusses significant references (review articles, research papers and international databases and reports), mostly published in the last 10 years. This review is aimed at addressing three key issues related to the better understanding of the BC role in AD processes: 1. Investigation of the influence of BC properties on AD performances and of their ability to counteract its main challenges; 2. Assessment of the optimal BC production chain (i.e. feedstock-pyrolysis-activation) to achieve the desired features; 3. Evaluation of the economic and environmental advantages connected to BC use in AD processes, compared to conventional solutions applied to address AD challenges

Desafíos del Estado colombiano en torno al aprovechamiento ilícito de oro y los cultivos de uso ilícito en la Amazonía: estudio de caso de San José del Fragua (Caquetá)

Las características geográficas de la Amazonía colombiana, sumadas a las dificultades de acceso al territorio y la baja presencia gubernamental, han creado un escenario en el que resulta posible el desarrollo de economías ilícitas, que en muchas ocasiones son fuente de financiación de agrupaciones criminales. En este orden de ideas, en este artículo se caracteriza la dimensión de la minería aurífera en la región, sus impactos en materia ambiental y social,  y su relación con los cultivos de uso ilícito. Todo esto, a partir del análisis de bases de datos oficiales, revisión de la producción científica existente, entrevistas semiestructuradas a mineros y cocaleros que se realizaron en el marco de un estudio de caso en San José del Fragua, Caquetá y derechos de petición a las autoridades ambientales

Desafios do Estado Colombiano em torno ao aproveitamento ilícito de ouro e os cultivos de uso ilícito na Amazônia: estudo de caso de San José del Fragua (Caquetá)

Las características geográficas de la Amazonía colombiana, sumadas a las dificultades de acceso al territorio y la baja presencia gubernamental, han creado un escenario en el que resulta posible el desarrollo de economías ilícitas, que en muchas ocasiones son fuente de financiación de agrupaciones criminales. En este orden de ideas, en este artículo se caracteriza la dimensión de la minería aurífera en la región, sus impactos en materia ambiental y social,  y su relación con los cultivos de uso ilícito. Todo esto, a partir del análisis de bases de datos oficiales, revisión de la producción científica existente, entrevistas semiestructuradas a mineros y cocaleros que se realizaron en el marco de un estudio de caso en San José del Fragua, Caquetá y derechos de petición a las autoridades ambientales.The geographical features of Colombian Amazon, the access difficulties to this territory,and a low governmental presence have created a scenario in which it is possible toperform illicit economies, which are a financing source for armed groups. Bearing this inmind, this research analyzes the role of the state regarding illegal gold mining activitiesin the region and its link with crops for illicit use through the official database analysis,a review of the present academic production, semi-structured interviews with minersand coca growers, and fieldwork in San José del Fragua (Caquetá). This study showsthat in the region, both illegal activities have a high impact on the deforestation ofnatural forests. Furthermore, these activities are common among the population dueto the high income they generate. In the case study, the communities alternate the twoactivities (illegal mining and illicit crops)